JP2010076606A - Driving assistance system of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving assistance system of a vehicle capable of determining the performance deterioration of a distance measuring device with an easy procedure. <P>SOLUTION: A maximum measured data is obtained (S2-S5) from all the distance data measured within the predetermined number of measuring times, and an inter-vehicle allowance distance is obtained (S6) by subtracting a control inter-vehicle distance from the obtained maximum measured distance. In the case where the obtained inter-vehicle allowance distance is a determined value set in advance or less, it is determined that there is a performance deterioration and its information is transmitted to a driver (S7, S10, S11). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a driving support apparatus for a vehicle.

  In recent years, driving support devices such as ACC (Adaptive Cruise Control) have been developed in order to reduce driving operations and improve safety. For example, ACC measures the distance to a preceding vehicle with a distance measuring device such as a laser radar, and automatically brakes when there is a possibility of collision with the preceding vehicle. In such a driving support device, the measurement performance of the distance measuring device is important, but it is affected by factors such as the weather and the degree of contamination of the preceding vehicle to be measured. It is necessary to let For example, in Patent Document 1, the degree of dirt on the preceding car is evaluated from the detected inter-vehicle distance and reflection intensity, and the ratio of the dirty preceding car to the total number of detected preceding cars is calculated. The control gain is set to a low value to shift to gentle tracking control.

JP-A-6-139499 Japanese Patent No. 3893912 Japanese Patent No. 3997189

  In Patent Document 1, when the preceding vehicle becomes dirty due to weather factors (rain, snow, fog, etc.), it is possible to change its control characteristics. However, since the measurement distance itself is decreasing, there is a possibility that the preceding vehicle capture is delayed and the deceleration control is not in time.

  A specific description will be given with reference to FIGS. It should be noted that the maximum distance that can be measured by the distance measuring device in an ideal state (a state in which there is no influence of factors such as weather and dirt level) is defined as a “measurement limit distance” and will be described below. In an ideal state, the distance measuring device of the host vehicle 10 can capture the preceding vehicle within the range up to the measurement limit distance. In that case, when the preceding vehicle 20 is detected at a preset deceleration start distance, deceleration control is started (see FIG. 5A).

  On the other hand, when the preceding vehicle becomes dirty due to weather factors (rain, snow, fog, etc.), the distance that can be measured by the distance measuring device will become shorter than the measurement limit distance, and it may be set depending on the situation. It will be shorter than the deceleration start distance. In such a case, the deceleration start distance is substantially a currently measurable distance, and the deceleration control is started only when the preceding vehicle 20 is detected at the currently measurable distance (FIG. 5 ( b)). Even in such a case, the driver himself assumes that the distance measuring device is functioning as usual, and does not notice that the deceleration start point is significantly shortened. And, since the deceleration control is actually delayed, there is a risk of collision. Therefore, in such a situation, it is necessary not only to continue the control by lowering the control gain, but also to make the driver recognize a decrease in the performance of the distance measuring device. It is also necessary to decelerate the vehicle by braking.

  In order to deal with such a problem, in Patent Documents 2 and 3, the detected signal level and RCS (laser reflection cross section) are monitored to determine performance degradation. , Complicated procedures and calculations are required.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle driving support device that can determine the performance degradation of the distance measuring device by a simple procedure.

A vehicle driving support device according to a first aspect of the present invention for solving the above-described problem is provided.
Drive means for driving the vehicle;
Braking means for braking the vehicle;
A distance measuring means for measuring the distance to the object;
Control means for controlling the driving means and the braking means so that the inter-vehicle distance becomes a desired control inter-vehicle distance based on the inter-vehicle distance measured by the distance measuring means;
Transmission means for transmitting information from the control means to the driver,
The control means includes
Find the maximum measurement distance that is the maximum measurement distance from all the distance data measured by the distance measurement means within a predetermined number of measurements or within a predetermined measurement time
Subtract the control inter-vehicle distance from the determined maximum measured distance to obtain the inter-vehicle margin distance,
When the obtained inter-vehicle margin distance is equal to or less than a predetermined determination value, it is determined that the performance of the distance measuring unit is degraded, and information on the performance degradation is transmitted to the driver by the transmission unit. And

A vehicle driving support apparatus according to a second invention for solving the above-described problems is
In the vehicle driving support apparatus according to the first aspect,
Furthermore, the control means includes
When the control means determines that the performance of the distance measuring means is reduced, at least one of suppression of acceleration in the driving means or deceleration by the braking means is performed.

A vehicle driving support device according to a third aspect of the present invention for solving the above-described problem is provided.
In the vehicle driving support apparatus according to the first or second invention,
The transmission means is at least one of display means for displaying performance degradation information and sound transmission means for transmitting performance degradation information by sound.

  According to the present invention, since the inter-vehicle margin distance determined from the difference between the maximum measurement distance that can be currently measured and the control inter-vehicle distance that is currently being controlled is determined, the device performance degradation is determined by a simple procedure. The performance degradation of the device can be determined and transmitted to the driver. As a result, since the driver can grasp the performance degradation of the device, it is possible to suppress the danger of collision due to the overconfidence of the device, and it is possible to suppress excessive approach to the preceding vehicle when the device performance is degraded under bad weather. Furthermore, it is possible to determine the performance degradation of the apparatus and to cooperate with control such as acceleration suppression and deceleration.

  Hereinafter, a vehicle driving support apparatus according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a block diagram showing a vehicle driving support apparatus according to the present invention, FIG. 2 is a diagram for explaining control of the vehicle driving support apparatus shown in FIG. 1, and FIG. It is a flowchart which shows control of the driving assistance device of the vehicle shown in FIG.

  As shown in FIG. 1, the vehicle driving support device of this embodiment includes a distance measuring device 11 (distance measuring means) that measures a distance to an object such as a preceding vehicle, and distance data measured by the distance measuring device 11. ECU 12 (electronic control device; control means), a display device 13 (display means, transmission means) for displaying guidance for transmitting information from the ECU 12 to the driver, and an engine 15 ( Driving means) and a brake 14 (braking means) for braking the vehicle.

  In the vehicle driving support apparatus of the present embodiment, the ECU 12 and the brake 15 are controlled so that the inter-vehicle distance becomes a desired control inter-vehicle distance based on the inter-vehicle distance with the preceding vehicle measured by the distance measuring device 11. 14 is controlled.

  As the distance measuring device 11, for example, a radar device such as a microwave or a millimeter wave, a laser radar device, a stereo camera, or the like is applicable. Further, as a transmission means for transmitting information from the ECU 12 to the driver, not only the display device 13 for displaying performance degradation information but also an alarm device (sound transmission means) for transmitting performance degradation information by sound is applied. Is possible.

  With reference to FIG. 1 and FIG. 2 and FIG. 3, control in the vehicle driving support apparatus of the present embodiment will be described.

  First, the maximum measurement distance is reset (step S1). For example, the maximum measurement distance is set to 0 m.

  Next, the distance measuring device 11 is used to measure the distance to an object such as a preceding vehicle and input to the ECU 12 (step S2). In this case, the object to be measured need not be limited to the vehicle (preceding vehicle), and any object can be used as long as the distance can be measured, such as a road structure (for example, a guard rail).

  Next, the measurement distance measured this time is compared with the maximum measurement distance measured so far. If measurement distance ≤ maximum measurement distance, the maximum measurement distance is not updated, and if measurement distance> maximum measurement distance Updates the maximum measurement distance (steps S3 to S4).

  Next, it is confirmed whether or not the measurement is equal to or greater than a predetermined number of times (step S5). If it is equal to or greater than the predetermined number of measurements, the process proceeds to the next step S6. Note that a predetermined measurement time may be used instead of the predetermined number of measurements.

  In steps S2 to S5, the maximum measurement distance that is the maximum measurement distance is obtained from all the distance data measured by the distance measurement device 11 within the predetermined number of measurements (or within the predetermined measurement time), This maximum measurement distance is the distance to the farthest object among the objects that can be measured by the current distance measurement device 11. In an ideal state (state without external factors such as weather), the “measurement limit distance” is obtained as the maximum measurement distance. On the other hand, when the preceding vehicle 20 is soiled due to weather factors (rain, snow, fog, etc.) or the distance measuring device 11 of the host vehicle 10 is soiled, a distance shorter than the measurement limit distance is obtained as the maximum measurement distance. It will be.

  Next, the inter-vehicle margin distance is obtained by subtracting the control inter-vehicle distance from the maximum measurement distance (step S6). Note that the control inter-vehicle distance may be the inter-vehicle distance that the ECU 12 is currently trying to maintain between the host vehicle 10 and the preceding vehicle 20. This control inter-vehicle distance varies depending on the travel environment, travel speed, and the like. For example, a distance that is about 2 to 3 seconds in terms of time is set as the control inter-vehicle distance. Of course, the distance between the control vehicles changes between the highway and the general road.

  Next, the obtained inter-vehicle margin distance is compared with a preset determination value (step S7). This determination value is used to determine performance degradation, and changes depending on the traveling environment, traveling speed, and the like. For example, the determination value is set to 10 m.

  When the inter-vehicle margin distance is larger than the determination value, the process proceeds to steps S8 and S9, it is determined that there is no performance degradation, and status guidance, for example, an indicator indicating a normal state is displayed on the display device 13.

  On the other hand, when the inter-vehicle margin distance is equal to or less than the determination value, the process proceeds to steps S10 and S11, where it is determined that there is a decrease in performance, and status guidance, for example, an indicator indicating an abnormal state is displayed on the display device 13, The driver will be notified of the performance degradation. In an abnormal state, not only visual guidance such as an indicator but also voice guidance may be performed. In addition to the guidance, in the control of the brake 14 and the engine 15, the control gain may be changed, the vehicle may be automatically decelerated, or acceleration may be suppressed.

  The vehicle driving support apparatus according to the present embodiment monitors the maximum measurement distance and the inter-vehicle margin distance as needed by sequentially performing the procedures shown in steps S1 to S11, and monitors the inter-vehicle margin distance. Thus, the performance degradation of the apparatus is determined and guidance is performed.

  An example of the control described above is shown in the graph of FIG. For example, FIG. 4 is based on the assumption that the distance measuring device 11 of the own vehicle or the preceding vehicle gets dirty with time. In such a situation, since the vehicle driving support device of this embodiment sequentially monitors the distance to the measurable object, the actual measurement distance by the distance measuring device 11 decreases with time. As a result, when the inter-vehicle margin distance is less than or equal to the determination value, it is determined that there is a performance degradation and the situation guidance is output.

  More specific control examples will be described by exemplifying numerical values. As shown in Table 1, for example, when the current control inter-vehicle distance is 50 m and the determination value is 10 m, the maximum measurement distance is changed. When the inter-vehicle margin distance changes and the maximum detection distance becomes 60 m, the inter-vehicle margin distance becomes 10 m. Therefore, it is determined that there is a decrease in performance, and the situation guidance is output.

  In addition, instead of simply determining with the determination value, as shown in FIG. 4 as well, the time transition of the inter-vehicle margin distance is monitored, and if the inter-vehicle margin distance tends to decrease, there is a decrease in performance. The situation guidance may be output at a timing earlier than the determination value. In this case, in the flowchart shown in FIG. 3, the inter-vehicle margin distance obtained in step S6 is recorded at any time during travel, and the presence or absence of performance deterioration is determined by observing the trend of the recorded inter-vehicle margin distance over time. That's fine.

  As described above, in the vehicle driving support device of the present embodiment, the driver can grasp the performance degradation of the device, so that the danger of collision due to the device overconfidence can be suppressed. As a result, it is possible to suppress excessive approach to the preceding vehicle when the device performance deteriorates under bad weather. Furthermore, it is possible to determine the performance degradation of the apparatus and to cooperate with control such as acceleration suppression during automatic acceleration and early start of deceleration.

  The present invention is applicable to a vehicle driving support device such as ACC (Adaptive Cruise Control).

It is a block diagram which shows the driving assistance device of the vehicle which concerns on this invention. It is a figure explaining control of the driving assistance device of vehicles shown in Drawing 1. It is a flowchart which shows control of the driving assistance device of the vehicle shown in FIG. It is a figure which shows the example of control in a present Example. It is a figure explaining the problem in a prior art.

Explanation of symbols

11 Distance measuring device 12 ECU
13 Display device 14 Brake 15 Engine

Claims (3)

Drive means for driving the vehicle;
Braking means for braking the vehicle;
A distance measuring means for measuring the distance to the object;
Control means for controlling the driving means and the braking means so that the inter-vehicle distance becomes a desired control inter-vehicle distance based on the inter-vehicle distance measured by the distance measuring means;
Transmission means for transmitting information from the control means to the driver,
The control means includes
Find the maximum measurement distance that is the maximum measurement distance from all the distance data measured by the distance measurement means within a predetermined number of measurements or within a predetermined measurement time
Subtract the control inter-vehicle distance from the determined maximum measured distance to obtain the inter-vehicle margin distance,
When the obtained inter-vehicle margin distance is equal to or less than a predetermined determination value, it is determined that the performance of the distance measuring unit is degraded, and information on the performance degradation is transmitted to the driver by the transmission unit. A vehicle driving support device. The vehicle driving support device according to claim 1,
Furthermore, the control means includes
When the control means determines that the performance of the distance measuring means is reduced, at least one of suppression of acceleration in the driving means or deceleration by the braking means is performed. . In the vehicle driving assistance device according to claim 1 or 2,
The vehicle driving support device according to claim 1, wherein the transmission unit is at least one of a display unit that displays performance degradation information and a sound transmission unit that transmits performance degradation information by sound.

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